Constipation can be caused by a poor diet, not drinking enough water and not going to the toilet as soon as you feel you need to. Pregnancy, a lack of exercise or movement (such as being ill in bed) and some medicines, including some painkillers, can also cause constipation.

However, many people take laxatives when they do not need to because they believe that they are constipated unless they go to the toilet every day. This is not the case. A useful definition of constipation is going to the toilet less frequently than is normal for you, and passing hard stools (faeces) when you do go.

Sodium picosulfate works by encouraging the muscles in your bowel to move waste products through your body. This helps you to go to the toilet. It usually has an effect within 6-12 hours. Sodium picosulfate preparations are available to buy without a prescription at pharmacies and other retail outlets.

Preparations containing sodium picosulfate (in combination with another laxative called magnesium citrate) are sometimes used to clear the bowel before some medical examinations. When it is used like this, you will be provided with sachets of powder by your hospital or clinic. You will also be given full instructions for how to use them.

The rest of the information in this leaflet is about sodium picosulfate when it is used for constipation.

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Before taking sodium picosulfate

To make sure this is the right treatment for you, ask for advice from a doctor or pharmacist before you start using sodium picosulfate if any of the following apply to you:

If you are pregnant, trying for a baby or breast-feeding. This is because, while you are expecting or feeding a baby, you should only take medicines on the recommendation of a doctor.

If it is for a child. This is because laxatives should only be given to children on the advice of a doctor or healthcare professional.

If you have severe pain in your tummy (abdomen) and feel sick.

If you have recently had any bowel or abdominal surgery, or if you have been told you have an inflammatory bowel condition.

If you are lacking in fluid in the body (dehydrated) or taking 'water' tablets (diuretics)

If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.

If you have ever had an allergic reaction to a medicine.

How to take sodium picosulfate

Before you start this treatment, read the manufacturer's printed information leaflet from inside your pack. The leaflet will give you more information about sodium picosulfate and a full list of side-effects which you may experience from taking it.

The dose for adults is 2-4 capsules or 5-10 ml of liquid. Take the capsules with a drink of water to help you swallow. Sodium picosulfate takes about 6-12 hours to work; therefore, it is best taken at bedtime.

If sodium picosulfate has been prescribed for your child, follow carefully the instructions you are given, as your doctor will adjust the dose according to their age and needs.

Sodium picosulfate should only be used for a short time. This is because your bowel can start to rely on this type of laxative to make it work rather than working on its own. If you are still constipated after taking it for five days, you should speak with your doctor.

Getting the most from your treatment

A healthy diet containing fibre (wholegrain breads and cereals, bran, fruit and green leafy vegetables) with six to eight full glasses of water each day and daily exercise are important in maintaining healthy bowel function. For people who have problems with constipation, food such as pastries, puddings, sugar, sweets, cheese and cake can make matters worse.

Can sodium picosulfate cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. These usually improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following side-effects continue or become troublesome.

Sodium picosulfate side-effects - these affect less than 1 in 10 people who take this medicine

What can I do if I experience this?

Loose or watery stools (diarrhoea)

Stop taking the sodium picosulfate. This can be a result of taking sodium picosulfate unnecessarily or for too long

Tummy cramps or discomfort, feeling dizzy

These should soon pass

Feeling sick

Stick to simple foods

If you experience any other symptoms which you think may be due to this medicine, speak with your doctor or pharmacist.

How to store sodium picosulfate

Keep all medicines out of the reach and sight of children.

Store in a cool, dry place, away from direct heat and light.

Important information about all medicines

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital at once. Take the container with you, even if it is empty.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

Never keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

British National Formulary; 71st Edition (Mar-Sep 2016) British Medical Association and Royal Pharmaceutical Society of Great Britain, London

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.